PTFE Tube Level Gauges

PTFE Tube Level Gauges Their performance core lies in the polytetrafluoroethylene (PTFE, commonly known as F4) material used for their lining or measuring tube:

· Ultimate Chemical Stability: Can withstand the vast majority of chemical media, including strong acids, strong alkalis, and organic solvents, and can even resist corrosion from aqua regia.

· Broad Temperature Range: Can typically operate stably within a wide temperature range of -60°C to +260°C, with the upper working temperature limit for some models reaching up to 270°C.

· Excellent Pressure Adaptability: Working pressure covers vacuum (e.g., -0.077 MPa) to positive pressure (commonly 1.6 MPa, with special designs allowing for higher).

· Surface and Electrical Properties: Smooth inner wall, non-stick, resistant to scaling, and offers excellent insulation.

Main Application Areas

It is specifically designed for level measurement scenarios involving strong corrosion, high purity, or sanitary requirements:

· Chemical and Pharmaceutical: Level monitoring in storage tanks and reactors for various strong acids (sulfuric acid, hydrochloric acid) and strong alkalis.

· Environmental Protection and Water Treatment: Corrosive liquid storage tanks in processes like pickling, electroplating, and wastewater treatment.

· Food and Specialty Industries: Processes involving high-purity media or requiring avoidance of metal ion contamination.

Advantages Compared to Other Level Gauges

Compared to other level measurement solutions that directly contact the medium, its core advantage lies in achieving safe, stable, and intuitive measurement in highly corrosive environments.

· Glass Tube Level Gauge

  · Main Advantage: Extremely low cost, most intuitive display.

  · PTFE Tube Advantage: Corrosion resistant, shatterproof, intrinsically safer.

· Magnetic Level Gauge (Stainless Steel)

  · Main Advantage: Robust structure, capable of remote transmission, wide applicability.

  · PTFE Tube Advantage: PTFE lining solves the measurement challenge for strongly corrosive media.

· Radar/Ultrasonic Level Transmitter

  · Main Advantage: Non-contact, easy installation, intelligent remote transmission.

  · PTFE Tube Advantage: Direct and reliable, cost-effective, unaffected by foam or vapor.

Usage Precautions

1. Temperature and Pressure Correlation: The mechanical strength of PTFE decreases as temperature rises. Note that the working pressure must be reduced as temperature increases. For example, the working pressure may drop to 0.2 MPa at 80°C.

2. Installation Requirements: Must be installed vertically. When connecting flanges, bolts should be tightened evenly in a diagonal pattern to avoid deformation or leakage of the measuring tube or liner due to installation stress.

3. Avoid Mechanical Damage: Do not forcibly pull or twist the instrument during installation to align connections, as this may damage the internal lining or structure.

4. Regular Inspection: Monitor the sealing integrity at process connections and observe the transparency of the measuring tube. Replace promptly if severe contamination or aging occurs after long-term use.

Selection Guide

You can clarify the selection by answering the following key questions:

1. What is the medium and operating condition? (Decisive Factor)

   · If the medium is strongly corrosive (e.g., acids, alkalis, organic solvents), or requires high purity and anti-adhesion, PTFE tube gauges are the primary choice.

   · Clarify the medium's working temperature and pressure to ensure they are within the instrument's rated range.

2. What measurement range is needed?

   · Determine based on equipment installation height. The conventional measurement range for PTFE tube level gauges varies from 300 mm to 4000 mm and can be customized as needed.

3. What output and functions are required?

   · Local Display Only: Choose the basic transparent PTFE tube direct-reading type, which has the simplest structure.

   · Require Remote Transmission or Control: Choose a magnetically coupled PTFE tube level gauge, which can be paired with a 4-20mA transmitter or level switch to achieve remote transmission, alarm, or interlock control.

4. How to Determine Connection Type and Material?

   · Connection Type: Primarily flange connections (e.g., DN20/DN25), which must match the equipment interface.

   · Main Body Material: Typically stainless steel lined with PTFE, balancing structural strength and corrosion resistance. The exterior can also be carbon steel with powder coating or stainless steel based on the environmental corrosiveness.

Summary and Core Recommendation

The PTFE tube level gauge is a classic and reliable solution for the challenging task of local visual level measurement of highly corrosive media. It sacrifices some high-pressure tolerance (compared to all-metal instruments) in exchange for unparalleled corrosion resistance safety and intuitiveness.

The core of selection lies in confirming the necessary condition of "strong corrosiveness." If your medium is ordinary water, oil, or mildly corrosive liquids, other level gauges might be more cost-effective. However, once strong acids, alkalis, or similar media are involved, the PTFE tube level gauge is often the most economical and direct safe choice.